I already have a bunch of lvl 2 training fields and a dungeon under construction. My current expansions are full and the next one is 500k, which would take days of saving up for. I have a hard time now with epic faerie forest, which is my furthest area. Not sure how far to upgrade my armors since none of them are the big 4. I do have 2 non + versions of the big for, one of which I've unlocked the + version of but can't craft until I unlock more areas.